In Acts 2:37–41, the crowd is pierced to the heart by Peter’s proclamation of the crucified and risen Jesus and asks the most urgent question of faith: “What shall we do?” Peter’s answer—repent and be baptized in the name of Jesus Christ for the forgiveness of sins—reveals that the gospel calls for a concrete response that brings forgiveness, the gift of the Holy Spirit, and entry into God’s renewed people. That day, about three thousand are baptized, showing that the church is born as a repentant, forgiven, Spirit-filled community shaped by the saving work of Christ.